Computers, printers, and other networked devices are organized into different kinds of networks. Two of the most widely used kinds of networks are local area networks (LANs) and wide area networks (WANs). LANs and WANs each have relative advantages and disadvantages. LANs are generally faster, less expensive, and easier to configure than WANs, but WANs may contain many more devices and may span much greater physical distances than LANs.
LANs and WANs each use different technical conventions and different network protocols for addressing devices in a given network. LANs generally use media access control (MAC) addresses, which are also called “physical addresses” because they are typically assigned to and physically embedded within a network interface controller (NIC) of a device by the NIC manufacturer when the NIC is made. The Ethernet protocols used in many LANs, for example, use MAC addresses as network addresses. By contrast, WANs often use internet protocol (IP) addresses as network addresses. IP addresses are generally not physically embedded or otherwise unique to a device; a given device may be identified by different IP addresses at different times. The widely used Dynamic Host Configuration Protocol (DHCP) used in many WANs, for example, assigns IP addresses to devices dynamically, an act which would not be needed if IP addresses were physically embedded in the devices.